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Lesson 2 · Bitcoin Nodes

What is a Bitcoin node?

A Bitcoin node is a computer running Bitcoin software that independently checks transactions, blocks and the rules of the network.

Beginner lesson8–10 minute readNo wallet required

Node in simple terms

Your own independent Bitcoin verifier

A Bitcoin node runs software that understands Bitcoin’s consensus rules. It receives transactions and blocks, checks them and decides whether they are valid.

Your node does not have to ask a company, miner or exchange for permission. It independently checks the same rules as other honest nodes on the network.

When you use someone else’s server, you are trusting them to provide accurate Bitcoin information. Running your own node allows you to verify that information yourself.

Simple definition

A Bitcoin node is software that independently checks and enforces Bitcoin’s rules.

Core responsibilities

What does a Bitcoin node actually do?

Verify transactions

A node checks whether each transaction follows Bitcoin's rules before accepting or sharing it.

Verify blocks

A node checks every block proposed by miners, including its transactions, proof of work and structure.

Enforce consensus rules

A node rejects blocks and transactions that break the rules, even when they come from a miner.

Share valid information

Nodes relay valid transactions and blocks to other peers across the Bitcoin network.

Store blockchain data

A full node can maintain a verified copy of Bitcoin's transaction history.

Answer wallet requests

A wallet can connect to your node to check balances and transactions without trusting another company's server.

Verification process

How your node handles network data

Your node does not accept information simply because another participant sent it. Every transaction and block must pass verification.

01

A transaction reaches your node

Your node receives the transaction directly from a connected peer or wallet.

02

The rules are checked

The node checks signatures, available funds, transaction format and whether the bitcoin has already been spent.

03

Valid transactions enter the mempool

Transactions that pass verification may be stored temporarily while waiting to be mined.

04

A miner proposes a block

The block may include transactions from the mempool and is broadcast to the network.

05

Your node verifies the block

The node checks the proof of work, block reward, transaction validity and consensus rules.

06

The block is accepted or rejected

A valid block is added to your node's verified chain. An invalid block is rejected.

Nodes

Verify and enforce

Nodes decide whether transactions and blocks follow Bitcoin’s consensus rules.

Miners

Propose new blocks

Miners gather transactions and compete to produce a valid proof-of-work block.

Miners can propose blocks, but nodes independently decide whether those blocks are valid. An invalid block is rejected regardless of how much computing power created it.

Node types

Different ways to connect to Bitcoin

Fully validating

Full node

Downloads and independently verifies Bitcoin's blockchain and consensus rules.

Fully validating

Pruned full node

Fully verifies the blockchain but removes older block files to reduce storage requirements.

Archival full node

Keeps the entire blockchain history available on disk after verification.

Light wallet

Uses less storage but usually depends on external servers or other nodes for some information.

Pruned nodes still fully verify Bitcoin

Pruning reduces storage by deleting older block files after they have been verified. It does not turn the node into a light client.

Why run your own node?

Verify instead of trust

Independent verification

You check Bitcoin's rules yourself instead of trusting an exchange, wallet provider or block explorer.

Improved privacy

Your wallet can ask your own node about transactions rather than revealing addresses to a third-party server.

Stronger self-custody

A wallet controls your private keys, while your node independently verifies what is happening on the network.

Network resilience

More independently operated nodes make Bitcoin harder to censor, disrupt or misrepresent.

Basic requirements

What do you need to run a node?

You can run Bitcoin Core on a desktop computer, small dedicated machine or home server. The exact requirements depend on whether you keep the full blockchain or use pruning.

Computer

Storage

Internet connection

Bitcoin Core software

You do not need to attach a wallet

Bitcoin Core can run as a network node without storing wallet keys or managing funds. You can connect a wallet later when you are ready.

Common misconceptions

What running a node does not mean

Running a node earns bitcoin.

A standard full node does not earn bitcoin. Mining is a separate activity that uses specialised hardware.

A node needs a wallet attached.

You can run a node without creating, importing or connecting any wallet.

A node controls the Bitcoin network.

One node does not control Bitcoin. Each node independently decides which information it accepts.

A node must stay online every second.

A node can be turned off. When restarted, it reconnects and catches up with blocks it missed.

A node needs an expensive gaming computer.

Bitcoin Core can run on modest hardware, provided there is enough storage, memory and a reliable internet connection.

Lesson summary

The important points

A Bitcoin node independently verifies transactions and blocks.

Nodes enforce Bitcoin's consensus rules and reject invalid information.

Miners propose blocks, while nodes determine whether those blocks are valid.

A pruned node still fully verifies the blockchain.

You can run a node without creating or connecting a wallet.

Running your own node improves verification, privacy and self-custody.

Peer-to-peer network

Rule enforcement

Independent operators